I talked with an Apple Employee the other day about my concerns. I told them my pods and pencil just arrived the day after I ordered. So everything was ready to be used but of course I can't because of iPad shipping "actions" 😂.
She told that they are aware of this situation, I cannot test or use my pencil before iPad arrives. In this case, they can extend the 14 day return deadline. She put a not on my "Apple support case" and made sure if I have any problems about it the next employee will know and help me through. I guess it will be more or less the same in every country but in any case you can call and ask them to make sure about this.